New Achievement to Access Spawn Mine

[rth081094]

First of all, four endermen wouldn't wreck you as long as you don't look at them and plus they are most likely going to teleport away. Also fighting a wither in a small space would wreck you no matter what armor you have on (This can be proven wrong if you are some type of Wither-killing ninja).
Additionally wouldn't it be way easier to just set up an arena with waves of mobs that spawn getting harder as it progresses... Idk just my opinion on this topic.